#nav_footer{
    height:50px;
}
.nav_footer {
    height:45px;
    line-height:45px;
    text-align:center;
    position:fixed;
    z-index:1200;
    bottom:0;
    left:0;
    right:0;
    width:100%;
    max-width:640px;
    margin:auto;
    background:-webkit-gradient(linear, 0 0, 0 100%, from(#6e6e6e), to(#3c3c3c));
}
.nav_footer a{
    display:inline-block;
    width:60px;
    height:100%;
    color:#fff!important;
    background:url('../img/tocenter.png') no-repeat center center;
    background-size:53px auto;
}
.nav_footer li:first-of-type a{
    text-indent:5px;
    background-image: url('../img/toleft.png');
    background-size:60px;
}
.nav_footer li:nth-of-type(2) a{
    text-indent:-5px;
    background-image: url('../img/toright.png');
    background-size:60px;
}

.box {
    width: 100%;
    display: -webkit-box;
    display: -moz-box;
    -webkit-box-orient: horizontal;
    -moz-box-orient: horizontal;
    -webkit-box-sizing: border-box;
    -moz-box-sizing: border-box;
}

.box > * {
    -webkit-box-flex: 1;
    -moz-box-flex: 1;
}